rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (9855 ticks this GP) idle=1ae4/1/0x4000000000000000 softirq=23743/23743 fqs=303
rcu: (t=10501 jiffies g=26581 q=1481 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 6141 jiffies! g26581 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=17571
rcu: rcu_preempt kthread starved for 6144 jiffies! g26581 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:27272 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5760 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 4c 1d 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 43 77 3c 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffc9000453f6f8 EFLAGS: 000002d3
RAX: ffffffff813a9538 RBX: 0000000000000003 RCX: ffff88802f045a00
RDX: 0000000000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffc9000453f7d0 R08: ffffffff911e75c7 R09: 1ffffffff223ceb8
R10: dffffc0000000000 R11: fffffbfff223ceb9 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff920008a7ee4
FS: 000055558da67500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055afe56d73e0 CR3: 000000002e936000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
kvm_wait+0x23d/0x2a0 arch/x86/kernel/kvm.c:1058
pv_wait arch/x86/include/asm/paravirt.h:598 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
__pv_queued_spin_lock_slowpath+0x613/0x9c0 kernel/locking/qspinlock.c:511
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x23e/0x2b0 kernel/locking/spinlock_debug.c:115
spin_lock_bh include/linux/spinlock.h:356 [inline]
lock_sock_nested+0x6a/0x100 net/core/sock.c:3547
lock_sock include/net/sock.h:1780 [inline]
tcp_recvmsg+0x1fb/0x830 net/ipv4/tcp.c:2607
inet_recvmsg+0x140/0x1f0 net/ipv4/af_inet.c:882
sock_recvmsg_nosec net/socket.c:1047 [inline]
sock_recvmsg net/socket.c:1069 [inline]
sock_read_iter+0x2db/0x3f0 net/socket.c:1139
call_read_iter include/linux/fs.h:2012 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x486/0x990 fs/read_write.c:470
ksys_read+0x151/0x260 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f091df58fd7
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffeaede39c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055558da67500 RCX: 00007f091df58fd7
RDX: 0000000000000004 RSI: 00007ffeaede3a1c RDI: 0000000000000003
RBP: 00007ffeaede3ec0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffeaede3a1c R14: 00007ffeaede3ab0 R15: 0000000000000000
CPU: 0 PID: 8912 Comm: syz.3.890 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x2e/0x60 kernel/kcov.c:216
Code: 48 8b 04 24 65 48 8b 0d c0 d2 7c 7e 65 8b 15 c1 d2 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 <74> 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b
RSP: 0018:ffffc90000005f30 EFLAGS: 00000246
RAX: ffffffff813b24f8 RBX: 1ffff92000000c01 RCX: ffff888028085a00
RDX: 0000000000000100 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffffc90000006058 R08: ffffc900000060d0 R09: 0000000000000021
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000007ff0
R13: ffffc90000006008 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007f38fe4816c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555591ffe4e8 CR3: 000000001b7dc000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
unwind_next_frame+0x128/0x2990 arch/x86/kernel/unwind_orc.c:482
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
skb_kfree_head net/core/skbuff.c:946 [inline]
skb_free_head net/core/skbuff.c:958 [inline]
skb_release_data+0x609/0x7f0 net/core/skbuff.c:988
skb_release_all net/core/skbuff.c:1054 [inline]
__kfree_skb net/core/skbuff.c:1068 [inline]
kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1104
dev_kfree_skb_any_reason+0x120/0x130 net/core/dev.c:3241
free_old_xmit_skbs+0x11a/0x3b0 drivers/net/virtio_net.c:780
start_xmit+0x16d/0x1470 drivers/net/virtio_net.c:2420
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3644 [inline]
dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660
sch_direct_xmit+0x251/0x4a0 net/sched/sch_generic.c:345
__dev_xmit_skb net/core/dev.c:3881 [inline]
__dev_queue_xmit+0x162a/0x3630 net/core/dev.c:4416
neigh_output include/net/neighbour.h:543 [inline]
ip_finish_output2+0xd97/0x1260 net/ipv4/ip_output.c:235
NF_HOOK_COND include/linux/netfilter.h:293 [inline]
ip_output+0x2a5/0x3a0 net/ipv4/ip_output.c:436
dst_output include/net/dst.h:467 [inline]
ip_local_out net/ipv4/ip_output.c:129 [inline]
__ip_queue_xmit+0x1056/0x1960 net/ipv4/ip_output.c:540
__tcp_transmit_skb+0x1dd6/0x3470 net/ipv4/tcp_output.c:1427
tcp_ack_snd_check net/ipv4/tcp_input.c:5738 [inline]
tcp_rcv_established+0xb22/0x1d70 net/ipv4/tcp_input.c:6184
tcp_v4_do_rcv+0x6d3/0xba0 net/ipv4/tcp_ipv4.c:1735
tcp_v4_rcv+0x2358/0x2a60 net/ipv4/tcp_ipv4.c:2167
ip_protocol_deliver_rcu+0x20a/0x3f0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x2c3/0x510 net/ipv4/ip_input.c:233
NF_HOOK+0x32d/0x3b0 include/linux/netfilter.h:304
dst_input include/net/dst.h:477 [inline]
ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
ip_sublist_rcv+0xa36/0xd60 net/ipv4/ip_input.c:639
ip_list_rcv+0x3ed/0x440 net/ipv4/ip_input.c:674
__netif_receive_skb_list_ptype net/core/dev.c:5689 [inline]
__netif_receive_skb_list_core+0x582/0x770 net/core/dev.c:5737
__netif_receive_skb_list net/core/dev.c:5789 [inline]
netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5880
gro_normal_list include/net/gro.h:451 [inline]
napi_complete_done+0x329/0x820 net/core/dev.c:6220
virtqueue_napi_complete drivers/net/virtio_net.c:450 [inline]
virtnet_poll+0xaa0/0x11e0 drivers/net/virtio_net.c:2236
__napi_poll+0xbb/0x460 net/core/dev.c:6650
napi_poll net/core/dev.c:6717 [inline]
net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5255
Code: 2e 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 43 32 38 09 e8 8e 0a 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc90003947820 EFLAGS: 00000282
RAX: 1f9d8b1bae1b6600 RBX: 0000000000000000 RCX: 1f9d8b1bae1b6600
RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffc90003947870 R08: ffffffff911e75a7 R09: 1ffffffff223ceb4
R10: dffffc0000000000 R11: fffffbfff223ceb5 R12: ffff888028085a00
R13: 1ffff110171c79a9 R14: dffffc0000000000 R15: ffff8880b8e3cd48
context_switch kernel/sched/core.c:5384 [inline]
__schedule+0x15b6/0x4660 kernel/sched/core.c:6700
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
class_preempt_destructor include/linux/preempt.h:478 [inline]
try_to_wake_up+0x6f5/0x10e0 kernel/sched/core.c:4356
wake_up_process kernel/sched/core.c:4481 [inline]
wake_up_q+0xb6/0x100 kernel/sched/core.c:1032
__mutex_unlock_slowpath+0x65c/0x6c0 kernel/locking/mutex.c:951
__do_sys_perf_event_open kernel/events/core.c:12952 [inline]
__se_sys_perf_event_open+0x1853/0x1c60 kernel/events/core.c:12601
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f38fd59de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f38fe481028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f38fd825fa0 RCX: 00007f38fd59de59
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007f38fd633e6f R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f38fd826038 R14: 00007f38fd825fa0 R15: 00007ffeddbaeac8